<?php	include "../db.php";	session_start();	$username = $_POST['username'];	$password = $_POST['password'];	$cat = $_POST['cat'];	$login_query = "select * from $cat where username='$username' && password='$password'";	$login_rs = mysql_query($login_query);	if(mysql_num_rows($login_rs)) {		$login_row = mysql_fetch_assoc($login_rs);		$_SESSION['user_id'] = $login_row['id'];		$_SESSION['username'] = $login_row['username'];		$_SESSION['category'] = $cat;		$category = $login_row['category'];		header("location:../$cat/profile.php?username=$username");	}	else header("location:login.php");?>